Effect of Seven Newly Synthesized and Currently Available Oxime Cholinesterase Reactivators on Cyclosarin-Intoxicated Rats

Seven new oxime-based acetylcholinesterase reactivators were compared with three currently available ones (obidoxime, trimedoxime, HI-6) for their ability to lessen cholinesterase inhibition in blood and brain of cyclosarin-treated rats. Oximes were given at doses of 5% their LD₅₀ along with 21 mg/kg atropine five min before the LD₅₀ of cyclosarin (120 ug/kg) was administered. Blood and brain samples were collected 30 minutes later. The greatest difference between acetylcholinesterase inhibition in blood of cyclosarin-treated rats was found after administration of HI-6 (40%), compared to 22% for trimedoxime and 6% for obidoxime. Only two of the seven newly synthesized oximes had any effect (K203 at 7%, K156 at 5%). Effective oximes against cyclosarin-inhibited plasma butyrylcholinesterase were HI-6 (42%), trimedoxime (11%), and K156 (4%). The oximes were less effective in brain than in blood, with reactivation values for HI-6 30% against acetylcholinesterase and 10% against butyrylcholinesterase. Values for newly synthesized oximes were less than 10% for K206, K269 and K203.     

Distributions of electric and elastic fields at domain boundaries

In this paper we describe the application of the finite element method (FEM) in modelling spatial distributions of electric and elastic fields in a ferroelectric crystals with two domains separated by a 90° domain wall. The domain boundary is idealized as a two-dimensional defect in an electro-elastic continuum. It represents the source of inhomogenity and internal distortion in both elastic and electric fields. The main results are distributions of electric field, strain and mechanical force along the domain boundary.     

A new investigation of the system Ni–P

The binary system Ni–P is one of the constituents of the ternary system Ni–P–Sn which provides the basic knowledge for understanding the interactions between Sn-based solders and common Ni(P) metallization. In this study a new version of the Ni–P phase diagram was established based on XRD, EPMA and DTA measurements. The present diagram differs in some important details from the literature version. For the phases Ni₅P₂ high temperature (HT) and Ni₁₂P₅ HT the existence of a considerable homogeneity range is proposed. In Ni₅P₂ the transformation between HT and low temperature (LT) modification comprises a peritectic and a eutectoid reaction, whereas for the transition in Ni₁₂P₅ two eutectoids are proposed. Unfortunately, the high temperature phases cannot be stabilized by quenching, so that all data have to rely on the results of thermal analyses. Furthermore, Ni₅P₄ was found to be formed by a peritectic reaction, and a eutectic was observed between Ni₅P₄ and NiP. The phase NiP_1.22 that had been reported in the literature could not be found at all. Although the experimental work was complicated by the high vapor pressure of phosphorus at P concentrations higher than 40 at.% (which caused the explosion of quartz tubes and prevented the preparation of equilibrium samples at higher temperatures), it could still be shown that the phase NiP₃ is probably stable down to room temperature in contrast to the literature reports.     

Electro-ultrasonic spectroscopy of polymer-based thick film layers

We have studied the properties of polymer-based thick film layers by electro-ultrasonic spectroscopy. Electro-ultrasonic spectroscopy method is based on the interaction between ultrasonic vibrations and electrical conductivity of solids. The ultrasonic vibrations of frequency f_U change the contact area between conducting grains in the thick film structure and then the resistance is modulated by the frequency of ultrasonic excitation. An intermodulation voltage is created on this structure. It depends on the value of AC current varying with frequency f_E and on the ultrasonic excited resistance change ΔR varying with frequency f_U. We have measured the intermodulation voltage U_m for a set of polymer-based thick film resistors made by different resistive pastes. It was found that for given sample the intermodulation component of frequency f_m = f_E − f_U increases linearly with electric excitation for the constant ultrasonic excitation. We have normalized the intermodulation voltage U_m by the electric current I_E and this quantity is proportional to the ultrasonic excited resistance change ΔR. The relative resistance change ΔR/R_X is of the order of 10⁻⁷–10⁻⁴. From the comparison of the results measured for the samples made by the same resistive pastes it follows, that relative resistance change ΔR/R_X can be used as an indicator of sample quality.     

1D-photonic crystals prepared from the amorphous chalcogenide films

We describe the preparation and optical properties of the 15-layer chalcogenide dielectric mirrors with the first order stop bands in near infrared range. The high refractive index Sb–Se and low refractive index Ge–S layers were deposited on silicon and glass substrates using thermal evaporation method. To centre the stop bands of the prepared chalcogenide mirrors at 1.55 μm, the layer thicknesses, d(Sb–Se) = 117 and d(Ge–S) = 183 nm, were calculated from the quarter wave stack condition. The optical reflectivity measurements revealed the total reflection from the 15-layer chalcogenide mirrors in the range of 1,400–1,600 nm for the unpolarized light with normal incidence. The effect of annealing on the optical properties of the prepared chalcogenide mirrors was studied as well. Using spectral ellipsometry, we examined the angular dependence of the multilayers reflectivity for the light with s- and p-polarization. The preparation of the dielectric mirrors for near infrared region from chalcogenide films seems to be possible exploiting good optical quality of chalcogenide films and their simple deposition.     

Study of TATP: Spontaneous Transformation of TATP to DADP

TATP, prepared in the presence of catalysts methanesulfonic, perchloric, or sulfuric acid, has been found to undergo transformation to DADP. However, no transformation occurs if TATP is purified or prepared involving catalysts such as hydrochloric acid, tin(IV) chloride, and nitric acid. The transformation has been monitored by the methods of DTA and HPLC.     

Convexity of Yield Surface with Directional Distortional Hardening Rules

The present paper examines the convexity of the yield surface in the directional distortional hardening models by Feigenbaum and Dafalias. In these models anisotropy develops through kinematic and directional distortional hardening, supplemented by the classical isotropic hardening, and the associative flow rule is used. However, the issue of convexity, which naturally arises due to the distortion of the yield surface, was not fully addressed. The present paper derives the necessary and sufficient conditions to ensure convexity of the yield surface for the simpler Feigenbaum and Dafalias models, but it is not as straightforward to derive corresponding conditions for convexity of the Feigenbaum and Dafalias model version which contains an evolving fourth-order tensor. In this case convexity will be addressed first in general and then at the limit state for which simple restrictions on the material constants to ensure convexity are derived. Numerical examples will show that some of the yield surfaces simulated in the original Feigenbaum and Dafalias publication will not stay convex if loaded beyond what was done in these publications. Therefore the material constants for these cases are recalibrated based on the derived relations for satisfaction of the convexity requirement, and the fitting of the yield surfaces is repeated with the new set of constants and compared with the previous case.     

IP home gateway as universal multi-purpose enabler for smart home services

There are many candidates for a communication infrastructure between the smart home gateway and service providers, distribution centers or end-users accessing smart home applications remotely. Optimally the access technology should be already deployed in order to minimize initial investments and in parallel must provide sufficient reliability and security even for critical applications. Therefore, we focused at already deployed platforms which have a strong potential to become the key communication technologies for smart home domain. Furthermore, we investigated the applicability of residential gateway access technology for emerging home automation services. Finally, we developed and demonstrate a middleware solution enabling the “state of technology” IP-based home gateway to serve as a universal multi-purpose enabler for connected home automation systems like alarm systems, smart metering and grid, photo-voltaic energy production systems, etc.